Mechanisms for reclinable seats

ABSTRACT

The invention provides a seat angle adjusting mechanism comprising a strut to extend between the two pivoted parts of the seat, the strut having teeth and being engaged with a housing, both the housing and the strut being pivotally mounted, one on each part of the seat, the strut also having a cam which can be turned about the strut axis to displace the strut laterally, about its pivot, and relative to the housing, to take the teeth into and out of mesh.

United States Patent 1 1 3,774,964

Turner Nov. 27, 1973 1 MECHANISMS FOR RECLINABLE SEATS 2,845,994 8/1958 Thompson 297 375 x 1,871,184 8/1932 Kochs [75] Hamid R! Turner Sum)" 535,999 3/1895 Sargent 297/375 Coldfield, England 73 Assignee: H. R. Turner (Willenhall) Limited, FOREIGN PATENTS OR APPLICATIONS w n n staffordshire England 1,498,802 10/1967 France 297/355 1,248,251 8/1967 Germany 297/361 [22] Filed: Jan. 4, 1972 [21] App]. No.: 215,326 Primary Examiner-James T. McCall Assistant ExaminerPeter A. Aschenbrenner Foreign Application Priority Data Atmmey Marshan & Yeastmg Jan. 8, 1971 Great Britain 922/41 Apr. 15, 1971 Great Britain 9,468/71 [57] ABSTRACT Nov. 3, 1971 Great Britain 51,020 71 The invention provides a seat angle ad usting mecha- 52 vs. Cl 297/366 297/361 297/375 mPrising a extend between the 1 51 Int. Cl lin 1/02 Pivm?l Parts the seat the Strut having teeth and [58] Field of Search....... 297/363 364 365 being engaged with a housing both the housing and 297/355 361 376 7 the strut being pivotally mounted, one on each part of 3. 74/527 the seat, the strut also having a cam which can be turned about the strut axis to displace the strut later- [56] References Cited ally, about its pivot, and relative to the housing, to

take the teeth into anout of mesh. UNITED STATES PATENTS 3,226,158 12/1965 Strien et a1. 297/361 7 Claims, 7 Drawing Figures MECHANISMS FOR RECLINABLE SEATS BACKGROUND OF THE INVENTION This invention relates to seats for use in, for example, motor vehicles, of the kind comprising a back-rest and a seat-base, the back-rest being adjustable in angle relative to the seat-base by means of an adjustment mechanism, and the invention also relates to mechanisms for use with such seatc.

SUMMARY OF THE INVENTION In accordance with the present invention, an adjustment mechanism for a reclinable seat comprises a bar provided with tooth formations along a portion of its length, a housing through which the bar extends,means pivotally mounting the bar for movement laterally of the housing, the housing having means for pivotally mounting it to the seat and also having complementary tooth formations, a cam extending along the length of the bar and co-operable with abutments on the interior of the housing, whereby movement of the cam about the axis of the bar effects said lateral movement and engagement or disengagement of the teeth.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I shows a portion of a vehicle seat provided with an adjustment mechanism:

FIG. 2 is an enlarged scale elevation of the mechanism viewed from the same direction as FIG. 1;

FIG. 3 is an elevation similar to FIG. 2 but viewed from a direction at right angles to that of FIG. 2;

FIG. 4 is a section on the line 44 of FIG. 2 with the parts in an adjusted position; and

FIG. 5 is a further section on the line 44 of FIG. 2 but showing the parts in a different position and disengaged ready for an adjustment to be effected;

FIG. 6 is a view generally similar to FIG. 1 but showing a modification and FIG. 7 is a section on the line 77 of FIG. 6 showing the parts midway between an engaged position and a disengaged position ready for an adjustment to be effected. I

DESCRIPTION or PREFERRED EMBODIMENTS Referring first to FIG. 1, the seat, of which portions only are shown," comprises a seat-base framelOand a seat-back frame 12. The frameslt) and 12 are pivoted together on a hinge axis 14 to allow of adjustment of the angle of back-rest tothe seat-base. To enable the seat back to be tipped forward, for example when used in a two door motor vehicle to allow access behind the seats to further seats or luggage space, the rearmost portions of frame are made as separate parts 16 pivoted at 18 and provided with a catch 20 spring urged by tension spring 22 so that the catch engages under an inverted channel member 24 extending across aportion of the seat frame. Thus in the position illustrated in FIG.1 the parts 16 are locked in position, but by release of the catch, that is anupward movement of the free end portion of the catch the complete back-rest with portions 16 can be tipped forwardly. The catch is arranged to have a self-camming action so as to re engage with the channel 24 when the seat-back is returned to the illustrated position from a tipped forward position. A I

The mechanism of the present inventionmay be best understood by considering the seat base and the seatback to form two sides of a triangle and these two to be connected by a third side or adjustable strut generally indicated by the reference 25 (FIG. 1) and by varying the effective length of the strut, the length of the third side of the triangle is varied, and hence the angle of inclination of the other two sides of the triangle relative to one another. It will be seen from this explanation that the strut can extend forwardly of the back-rest and above the seat-base (as illustrated in FIG. 1) or alternatively by extending the back-rest beyond the hinge axis 14 the mechanism and strut can be located wholly below the seat base and again forwardly of the backrest; or by extending the seat-base frame rearwardly of the hinge axis 14 the mechanism can be located behind the back-rest, either above the seat-base frame or if the back-rest is also extended beyond the hinge axis '14, below the seat-base frame. Each of these possibilities may have advantages in particular circumstances, and since the construction of strut may be similar in all possibilities, we have elected to describe two of the possibilities, one with respect to FIGS. 1 to 5 and the other in connection with FIGS. 6 and 7.

Turning now to FIGS. 1 to 5, the strut will be further described. As illustrated it comprises a bar or rod 30 which requires to be provided with a series of (preferably regularly) spaced slots or projections, and in the form illustrated and for conveniences of manufacture a continuous screw-thread is formed along this length of the rod.

The rod is generally L-shaped having a short limb 32 projecting at'right angles to the screwed length and formed with a stud 34 which is received through an ap erture ina lug 36 (FIG.1) fixed to the seat base, the bar being rendered captive to the lug by a nut 38, but being pivotal about the axis of the stud portion 34, so that considered from the FIG.- 1 view point, the strut can pivot to different angles relative to the seat-base and back-rest.

The bar extends through a housing 40 which is similarly provided with a stud 42 and nut 44 pivotally mounting the housing upon a lug 46 fast with the backrest frame, and it will be appreciated that in angular adjustment of thev back-rest frame relative to the seatbase, the axis of stud 42 swings about the axis of stud 34, and the housing pivots to allow the bar to assume the different angles previously mentioned. At the same time, the housing moves along the length of the bar, and the effective length of the strut may be considered as the portion between the two studs 43 and 42.

The housing is shown in cross-section in FIGS. 4 and 5, and it will be noted that it includes a generally semicylindrical portion 50 provided with projections or grooves 52 corresponding to the grooves or projections on the bar in cross-sectioiial shape, depth and pitch. When the bar is received in the portion 50, as shown in FIG. 4, the ribs and grooves mesh to hold these parts fixed against relative displacement and hence hold the back-rest against pivoting about the axis 14, and when in the disengaged position as in FIG. 5 there is no obstacle-for the bar moving freely through the housing. The wall 54 of the housing immediately opposite to the portion 50 is spaced an appropriate distance from the portion 50 to prevent excess movement of the bar relative to the housingin a direction transverse to the bar axis and also forms the abutment for a camming function hereinafter explained.

A cam is formed as a sheet metal pressing and comprises a longitudinal portion 60 conveniently of channel section for strength, and unitary with an end portion 62 which is pinned to the end of the bar 30 so as to mount the cam for pivotal movement about the axis of the bar. The opposite end of the portion 60 is provided with a clip portion 64 which substantially encircles the bar near the limb 32 thereof and also with a shield portion 66 which is generally cylindrical and forms an extension of the cam beyond the limb 32. Integral with the shield portion is a handle stem 68 terminating in an operating handle 70 which is inclined to the axis of the bar so as to facilitate applying a twisting movement to the shield and to the cam to turn the latter about the axis of the threaded or otherwise grooved portion of the bar. A torsion spring 72 is wound around the handle stem 68 and has one tail engaged with the shield portion 66 and an opposite tail 74 hooked about the bar. The spring is located in and has the function of rotating the shield, together with the cam clockwise as shown in FIG. 4 and FIG. 5 so that the parts naturally assume the FIG. 4 position. In rotation for example from the FIG. 5 position to the FIG. 4 position the cam part 60 encounters the wall 54 and effects a displacement of the bar into the recess 50 so as to cause the teeth engagement. The handle may be turned in an anti-clockwise direction as viewed in FIG. 5 against the torsion spring, and then one lateral edge of the cam portion 60 abuts the internal shoulder 80 of the housing (see FIG.5) to lift the bar out of the recess 50 and effect the disengagement.

The operation of the strut will now be clear; to adjust the angle of the seat-back it is only necessary to turn the handle in the app'ropriate direction, move the seat back, and release the handle whereupon the parts will re-engage. The seat-back may be urged about the axis 14 in an anti-clockwise direction as viewed in FIG. 1 by a torsion bar or other spring means (not shown) so as to return it towards a more upright or forward position, so that in angular adjustments of this kind the seat occupant turns the handle and leans forwardly and allows the seat-back to follow his movement. To adjust the seat-back in the opposite direction the handle is turned and the occupant leans backwardly displacing the back-rest against the spring means.

If the seat back should come to rest in a position where the two sets of teeth are not perfectly aligned for re-engagement, the bar will effect a slight longitudinal movement relative to the housing during the meshing.

It is found possible with the construc ton of FIGS. 1 to 5 to provide for very small increments of adjustment of the order of one degree or less than one degree, whilst providing sufficient rigidity and robustness to meet current requirements for motor vehicle seats.

It will be appreciated that it is only necessary to provide the strut at one side of a seat although in any seat construction designed for a particularly large load the struts could be duplicated and connected together for synchronous or substantially synchronous disengagement and re-engagement.

The shield 66 is open on one side, as seen in FIG. 1 and normally the open side will face the side of the seat so that the spring is protected from view by the shield. It will also be appreciated by those skilled in the art that a seat provided with this particular adjustment mechanism will be particularly easy to trim and upholster and indeed is particularly adapted for separate upholstery of the seat frame and the back-rest prior to connection of the two together.

In the modification shown in FIGS. 6 and 7, the seat base may be considered as being extended rearwardly beyond the pivotal axis 114 of the back-rest 112, and the strut is connected between the rearmost extension of the base 110 and a continuation of the back-rest frame beyond the pivotal axis.

The mechanism in the case of FIG. 6 and FIG. 7 comprises a strut having a portion generally similar to the portion 30 and provided with a metal pressing 132 forming a ball joint within a socket 134 provided in the seat base frame and an end portion 136 of the strut extends through an elongated slot 138 in the socket, the strut having an'abutment 169 to locate it axially with respect to the socket 134 and terminating in a handle portion 170. The housing 140 is generally similar to that in the first described arrangement but in this instance the cam extends along the length of the ribbed or threaded portion 130 only, and is rivetted or otherwise fixed to the threaded portion by fixtures 162. The action here is that the threaded portion itself is turned by the handle to take the cam against shoulder and lift the threaded portion out of the threaded recess 150, and in the opposite direction the cam abuts wall 154 for re-engagement. The strut is spring-urged to the engaged position, conveniently by a torsion spring not shown. During adjustment, the strut pivots about the ball joint end and the housing pivots about the back-rest extension end.

I claim:

1. An adjustment mechanism for a reclinable seat, comprising a bar provided with tooth formations along a portion of its length, and a housing through which the bar extends, having tooth formations to engage those on the bar, one of the bar and housing being pivotally mounted on a seat and the other being pivotally mounted on a seat back, wherein the improvement comprises a quick-acting releasing and locking device including a cam which extends along and is mounted on the bar, and means for rotating the cam about an axis extending longitudinally of the bar, the housing having portions which engage the cam in one position thereof to hold the tooth formations of the bar and housing in mesh, and which engage the cam in another position thereof to shift the bar laterally of the housing and thereby disengage the tooth formations of the bar and housing.

2. Mechanism as claimed in claim 1, wherein the cam is fast with the bar and turns with the bar.

3. Mechanism as claimed in claim 1, wherein the cam is pivotally mounted on the bar and turns relative to the bar.

4. Mechanism as claimed in claim 1, wherein the cam is integral with a shield which extends beyond the bar and carries a handle for turning the cam.

5. Mechanism as claimed in claim 1, wherein the bar is substantially L-shaped and one limb of the bar forms a pivotal mounting for the bar.

6. Mechanism as claimed in claim 1, wherein a torsion spring is provided for turning the cam towards the engaged position of the teeth.

7. A reclinable seat comprising seat-frame and backrest frame hinged together about a fixed axis and provided with a mechanism as claimed in claim I, extending as the third side of a triangle of which the seatframe and the back-rest frame or extension of either or both of them form the other two sides.

a: w i 

1. An adjustment mechanism for a reclinable seat, comprising a bar provided with tooth formations along a portion of its length, and a housing through which the bar extends, having tooth formations to engage those on the bar, one of the bar and housing being pivotally mounted on a seat and the other being pivotally mounted on a seat back, wherein the improvement comprises a quick-acting releasing and locking device including a cam which extends along and is mounted on the bar, and means for rotating the cam about an axis extending longitudinally of the bar, the housing having portions which engage the cam in one position thereof to hold the tooth formations of the bar and housing in mesh, and which engage the cam in another position thereof to shift the bar laterally of the housing and thereby disengage the tooth formations of the bar and housing.
 2. Mechanism as claimed in claim 1, wherein the cam is fast with the bar and turns with the bar.
 3. Mechanism as claimed in claim 1, wherein the cam is pivotally mounted on the bar and turns relative to the bar.
 4. Mechanism as claimed in claim 1, wherein the cam is integral with a shield which extends beyond the bar and carries a handle for turning the cam.
 5. Mechanism as claimed in claim 1, wherein the bar is substantially L-shaped and one limb of the bar forms a pivotal mounting for the bar.
 6. Mechanism as claimed in claim 1, wherein a torsion spring is provided for turning the cam towards the engaged position of the teeth.
 7. A reclinable seat comprising seat-frame and back-rest frame hinged together about a fixed axis and provided with a mechanism as claimed in claim 1, extending as the third side of a triangle of which the seat-frame and the back-rest frame or extension of either or both of them form the other two sides. 